Only two counties have more men, with San Francisco leading the way with about 104 men per 100 women, while the rest range from nearly equal numbers to only 95.3 men per 100 women in Contra Costa.#1. San Francisco — 103.9 men per 100 women#2. Santa Clara — 101.4 men per 100 women#3. Napa — 98.9 men per 100 women#4. Solano — 98.8 men per 100 women#5. San Mateo — 97 men per 100 women#6. Alameda — 96.1 men per 100 women (tied with Sonoma)#7. Sonoma — 96.1 men per 100 women (tied with Alameda)#8. Marin — 95.6 men per 100 women#9. Contra Costa — 95.3 men per 100 womenThe high number of men in San Francisco may be traced to the male-dominated tech industry, although it’s difficult to pinpoint one reason. Women searching for a partner, however, might not want to move to Walnut Creek, where there are only 95 men per 100 women.
Source: U.S. Census Bureau American Community Survey, Table S0101